Volvo D12, Operator'S Manual

Page: 76 / 214

72 Oil System
Wear Particles
The analysis values used for comparison
with each other must always come from the
same engine. The results must be evalued
with the knowledge of where the particles
originate from. The particle level (ppm) de-
pends on: — Oil and filter system total volume
— Oil volume when taking sample
— Oil consumption
— Driving conditions, fuel consumption
— Time between oil changes
Wear
Particles:
Cause/Origin Normal Levels
(ppm)
Fe - Iron Crankshaft, liners, camshaft, tappet, valve guides <100
Pb - Lead Big end and main crankshaft bearing shells <20
Cu - Copper Big end and main crankshaft bearing shells <20
Sn - Tin Surface layer of sliding bearings <20
Cr - Chrome Piston rings, valve rod <10
Al - Aluminum Pistons <10
Ni - Nickel Layer between the surface and copper layers on a
sliding bearing. <5
Si - Silicon Sand, dirt, etc. <20
Insolubles Carbonized oil, combustion particles, soot <1.8%
(by weight)
Water Coolant liquid, condensation water <0.1%
(by weight)
Fuel Dilution Incomplete combustion <3.0%
(by weight)
Antifreeze - Gly-
col High levels of sodium and boron indicate coolant
leak Should not
occur
Total Base Num-
ber (TBN)
1
TBN shows the remaining alkalines used for acid
neutralization >4.0
> = more than; < = less than
1
According to ASTM D2896
Recommendations
To get the best service life out of the en-
gine, use oil sampling in addition to regular maintenance. Oil analysis should only be